Lifting off near sunset, the 20-story rocket left a colorful trail of exhaust that turned bright white when the Delta IV climbed high enough to catch the day's last sunlight, as it streaked northeast over the Atlantic Ocean through a perfectly clear sky.

Two solid rocket motors burned out and tumbled away less than two minutes into the flight.

The hydrogen-fueled rocket's first stage separated and the payload fairing jettisoned as planned just over four minutes in, and the upper stage engine successfully completed its first of two planned burns.

Atop the rocket was the sixth in a series of 12 satellites upgrading the GPS constellation, which includes about 30 operational satellites flying 11,000 miles above Earth.

The constellation supports military operations and is one of the best known, given its wide use by civilians for everything from driving directions to the timing of financial transactions.

The Boeing-built spacecraft was scheduled to separate over the southern Indian Ocean, southwest of Australia, around 11:24 p.m. EDT.

Launch came on the second attempt, after poor weather scrubbed a first try Thursday.

It was ULA's fifth launch of the year and the 26th by a Delta IV since its debut in 2002.

The launch was the first of two ULA plans from Cape Canaveral within six days. The company's Atlas V rocket is targeting a liftoff Thursday with a classified National Reconnaissance Office satellite.